std_linear_congruential_engine.3cxx

Langue: en

Version: 356185 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

std::linear_congruential_engine -

A model of a linear congruential random number generator.

SYNOPSIS


Public Types


typedef _UIntType result_type

Public Member Functions


linear_congruential_engine (result_type __s=default_seed)

template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, linear_congruential_engine>::value> ::type> linear_congruential_engine (_Sseq &__q)

void discard (unsigned long long __z)

result_type max () const

result_type min () const

result_type operator() ()

void seed (result_type __s=default_seed)

template<typename _Sseq > std::enable_if< std::is_class< _Sseq >::value >::type seed (_Sseq &__q)

Static Public Attributes


static const result_type default_seed

static const result_type increment

static const result_type modulus

static const result_type multiplier

Friends


template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &, const std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &)

bool operator== (const linear_congruential_engine &__lhs, const linear_congruential_engine &__rhs)

template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &, std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &)

Detailed Description

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> class std::linear_congruential_engine< _UIntType, __a, __c, __m >

A model of a linear congruential random number generator.

A random number generator that produces pseudorandom numbers via linear function: \

The template parameter _UIntType must be an unsigned integral type large enough to store values up to (__m-1). If the template parameter __m is 0, the modulus __m used is std::numeric_limits<_UIntType>::max() plus 1. Otherwise, the template parameters __a and __c must be less than __m.

The size of the state is $1$.

Definition at line 157 of file random.h.

Member Typedef Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> typedef _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::result_typeThe type of the generated random value.

Definition at line 166 of file random.h.

Constructor & Destructor Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine (result_type __s = default_seed) [inline, explicit]

Constructs a linear_congruential_engine random number generator engine with seed __s. The default seed value is 1. Parameters:

__s The initial seed value.

Definition at line 184 of file random.h.

References std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> template<typename _Sseq , typename = typename std::enable_if<!std::is_same<_Sseq, linear_congruential_engine>::value> ::type> std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine (_Sseq & __q) [inline, explicit]

Constructs a linear_congruential_engine random number generator engine seeded from the seed sequence __q. Parameters:

__q the seed sequence.

Definition at line 197 of file random.h.

References std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().

Member Function Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> void std::linear_congruential_engine< _UIntType, __a, __c, __m >::discard (unsigned long long __z) [inline]

Discard a sequence of random numbers. Todo

Look for a faster way to do discard.

Definition at line 247 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::max () const [inline]

Gets the largest possible value in the output range. Todo

This should be constexpr.

Definition at line 238 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::min () const [inline]

Gets the smallest possible value in the output range. The minimum depends on the __c parameter: if it is zero, the minimum generated must be > 0, otherwise 0 is allowed.

Todo

This should be constexpr.

Definition at line 229 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> result_type std::linear_congruential_engine< _UIntType, __a, __c, __m >::operator() () [inline]

Gets the next random number in the sequence.

Definition at line 257 of file random.h.

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m> template<typename _Sseq > std::enable_if< std::is_class< _Sseq >::value >::type std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed (_Sseq & __q)

Reseeds the linear_congruential_engine random number generator engine sequence using values from the seed sequence __q. Parameters:

__q the seed sequence.

Seeds the LCR engine with a value generated by __q.

Definition at line 142 of file random.tcc.

References std::__lg(), and std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().

template<typename _UIntType , _UIntType __a, _UIntType __c, _UIntType __m> void std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed (result_type __s = default_seed)

Reseeds the linear_congruential_engine random number generator engine sequence to the seed __s. Parameters:

__s The new seed.

Seeds the LCR with integral value __s, adjusted so that the ring identity is never a member of the convergence set.

Definition at line 126 of file random.tcc.

Referenced by std::linear_congruential_engine< _UIntType, __a, __c, __m >::linear_congruential_engine(), and std::linear_congruential_engine< _UIntType, __a, __c, __m >::seed().

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits > std::basic_ostream<_CharT, _Traits>& operator<< (std::basic_ostream< _CharT, _Traits > &, const std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &) [friend]

Writes the textual representation of the state x(i) of x to __os. Parameters:

__os The output stream.
__lcr A % linear_congruential_engine random number generator.

Returns:

__os.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> bool operator== (const linear_congruential_engine< _UIntType, __a, __c, __m > & __lhs, const linear_congruential_engine< _UIntType, __a, __c, __m > & __rhs) [friend]

Compares two linear congruential random number generator objects of the same type for equality. Parameters:

__lhs A linear congruential random number generator object.
__rhs Another linear congruential random number generator object.

Returns:

true if the infinite sequences of generated values would be equal, false otherwise.

Definition at line 275 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> template<typename _UIntType1 , _UIntType1 __a1, _UIntType1 __c1, _UIntType1 __m1, typename _CharT , typename _Traits > std::basic_istream<_CharT, _Traits>& operator>> (std::basic_istream< _CharT, _Traits > &, std::linear_congruential_engine< _UIntType1, __a1, __c1, __m1 > &) [friend]

Sets the state of the engine by reading its textual representation from __is. The textual representation must have been previously written using an output stream whose imbued locale and whose type's template specialization arguments _CharT and _Traits were the same as those of __is.

Parameters:

__is The input stream.
__lcr A % linear_congruential_engine random number generator.

Returns:

__is.

Member Data Documentation

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> const _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::increment [static]An increment.

Definition at line 171 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> const _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::modulus [static]The modulus.

Definition at line 173 of file random.h.

template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> const _UIntType std::linear_congruential_engine< _UIntType, __a, __c, __m >::multiplier [static]The multiplier.

Definition at line 169 of file random.h.

Author

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